Ditch building machine

ABSTRACT

A ditch building machine has a front lister on which a prime mover and hydraulic pump are mounted and has a forward extending steering tongue which may be pivoted about its transverse horizontal and vertical axes. Behind the front lister are movable listers pivotally attached about a vertical axis to vary the width of the bottom of the ditch. Behind each movable lister is a moldboard pivoted thereto about both vertical and transverse horizontal axes. The rearward end of each moldboard is supported by a ground wheel which rests on the ground to the outside of the ditch. Structure is provided for controlling the angle of the moldboard relative to the longitudinal horizontal axis of the machine and relative to the horizontal to vary the width and depth of the ditch (and likewise the slope of the sides). Spoil blades are pivotally mounted to the rear of the moldboards to smooth the banks ahead of the rear wheels.

United States Patent [54] DITCH BUILDING MACHINE 11 Claims, 18 DrawingFigs.

52 U.S.Cl 37/98, 280/4323, 180/792 [51] 1nt.Cl EOZf5/02 37/98;

[50] Field of Search 2,684,543 7/1954 Cundiff, Sr. 37/98 2,784,5073/1957 Kinsinger 37/98 3,356,382 12/1967 Fay 280/4323 3,451,498 6/1969Molby 180/792 3,059,714 10/1962 Johnson 280/492 X 3,123,381 3/1964 Poore280/492 UX 2,668,376 2/1954 13115008.... 37/98 3,032,903 5/1962 Ede37/193 3,314,690 4/1967 Bunchak 180/792 X FOREIGN PATENTS 121,960 8/1946Australia 37/98 Primary Examiner-Robert E. Pulfrey AssistantExaminerClifford D. Crowder Attorney-Julian Caplan ABSTRACT: A ditchbuilding machine has a front lister on which a prime mover and hydraulicpump are mounted and has a forward extending steering tongue which maybe pivoted about its transverse horizontal and vertical axes. Behind thefront lister are movable listers pivotally attached about a verticalaxis to vary the width of the bottom of the ditch. Behind each movablelister is a moldboard pivoted thereto about both vertical and transversehorizontal axes. The rearward end of each moldboard is supported by aground wheel which rests on the ground to the outside of the ditch.Structure is provided for controlling the angle of the moldboardrelative to the 1ongitudinal horizontal axis of the machine and relativeto the horizontal to vary the width and depth of the ditch (and likewisethe slope of the sides). Spoil blades are pivotally mounted to the rearof the moldboards to smooth the banks ahead of the rear wheels.

PATENTEU mum 19m SHEET 2 BF 7 INVENTOR.

mm 2 @0172 BY PATENTEUAUB31 I97! SHEET w of 7 INVIZNTOR.

/([/V/VH// l. GOUZ BY 2 ATTORNEY PATENTEB M831 um SHEET 8 UF 7 INVENTOR.BY MAW/5TH E MHZ ATTUKA/EY PATENTED M831 I97! SHEET 7 [IF 7 FNVENTm/A/UH 2 601 U avjvfu L ATTUKNEV DITCII BUILDING MACHINE This inventionrelates to a new and improved ditch builder machine. More particularly,the invention relates to a tractor drawn machine which plows atrapezoidal cross section ditch or cleans a previously excavated ditchof the type used for irrigation and the like. Ditch building machines ofthis general type have a steering section at the front, a fixed listeror plowlike portion, an adjustable lister on either side of the rear ofthe fixed lister, and a moldboard on each side at the back of eachadjustable lister. The fixed and adjustable listers govern the width ofthe bottom of the ditch and the moldboard governs the width and slope ofthe sides of the ditch. The present invention comprises improvements inthe construction, and particularly in the actuation of the machine partswhich have been mentioned.

With respect to the steering portion of the machine, the presentinvention takes advantage of the balancing and leveling efiect of thefront axle suspension. Provision is further made during transport of themachine in a truck so that the steering tongue can be turned backwardsagainst the moldboard, thereby reducing the overall length of themachine and facilitating truck transport.

With respect to the adjustable listers, provision is made for amechanism which enables the machine to accommodate between a 2% foot and6 foot bottom width of the ditch. Such adjustability is accomplished byuse of a single hydraulic cylinder which acts upon a hinged master platewhich is in turn connected by ball and socket joints to the adjustablelisters.

A still further feature of the invention is the use of a main frame tubewhich is hinged about a transverse horizontal pivot to the back of thefront lister and is hinged at the rear to a subframe containing portionsof the actuating mechanism for the moldboards and also containing theoperators seat and controls. The tube is pivoted in conjunction with aparallel bar hinged to the same members as the tube which insures thatthe rear mechanism is always parallel to the front lister, and since thefront lister is horizontal, the rear mechanism which has been describedand particularly the operator's seat is also horizontal. The arrangementwhich has been described further improves the actuation of the spreadingand elevating of the moldboards and minimizes danger of collapse of suchmechanism. In addition, the mounting of the seat in the fashion whichhas been described insures that the operator is never elevated as highas the moldboard, a relationship which is of particular value where deepditches are being dug.

Another feature of the invention relates to the main moldboard hinge,whereby the moldboard is hinged to the movable lister. Such hingecomprises two axes which are perpendicular to each other andintersecting adjacent the bottom rear corner of the adjustable lister.This hinge arrangement hay a number of advantages. One such advantage isthat the moldboard cutting edges remain closer to the Iister cuttingedges in shallow and also in deep ditches. Another advantage is that aclean, sharp comer is formed at the bottom of the ditch. Still anotheradvantage is the fact that the inward and outward movement of themoldboard is facilitated.

Another feature of the invention is the assembly for mounting the guidefor the spreader arms. As has been stated, the Iister and the base ofthe spreader arm guide assembly are maintained horizontal in accordancewith the present invention at all times. Such relationship is importantbecause the spreader arms are intended to be vertical at all times sothat bending stresses on the spreader arms are not excessive.

Another feature of the invention is the fact that the spreader arms forthe moldboards are maintained vertical. The guide assembly is, as hasbeen stated, maintained horizontal. The axes for hinging the arms to themoldboard are maintained vertical, and the arms themselves are linkedtogether at onehalf of their total width. This construction enables thespreader arms to actuate the moldboard for width and height adjustmentthereof.

One of the important features of the present invention whichparticularly distinguishes this machine from previous machines is thefact that the rear end of each moldboard is supported by a wheel whichis mounted in outrigger fashion on the side of the ditch rather thanbeing supported bythe bottom of the ditch. In previous ditch buildingmachines, the support for the rear end has rested on the bottom of theditch and thus necessarily has been of limited width. By supporting themoldboards on the bank to either side of the ditch, great stability isachieved.

Still another feature of the invention is the mounting of the rearwheels so that they are automatically guided in the same direction asthe front wheels. Preferably the wheels are supported in conjunctionwith the mounting of spoiler wings which are blades moving ahead of therear wheels and smoothing the bank. Preferably, the spoiler wing ishinged along an axis which is common to the wheel caster pin, and therear wheels are hinged longitudinally with the same caster. Thisarrangement facilitates mounting of the wheels and of the spoiler.

Another feature of the invention is the fact that the arm which controlsthe spoiler may be adjusted to such a position as to bring the spoilblade to a straight back position during transport of the machine. Sucharrangement permits the machine to be so compactly adjusted that itsoverall width complies with the highway width of load regulations.

Other objects of the present invention will become apparent upon readingthe following specification and referring to the accompanying drawingsin which similar characters of reference represent corresponding partsin each of the several views.

In the drawings:

FIG. I is a side elevational view of a portion of the machine withelements on the near side thereof removed to reveal internalconstruction.

FIGS. 2 and 2A are composite top plan views of the machine.

FIG. 3 is a perspective view of the forward or towing section of themachine.

FIG. 4 is a schematic plan showing adjustment of the moldboard width.

FIG. 5 is a front elevational view of the structure of FIG. 41 alsoshowing height adjustment of the moldboard.

FIG. 6 is a view similar to FIG. 5 showing the moldboards folded toretracted position.

FIG. '7 is an enlarged sectional view partly broken away in sectionshowing the actuating mechanism for the movable listers.

FIG. 8 is a top plan of the structure of FIG. 7.

FIG. 9 is a perspective view of the hinge of the moldboard to theadjustable listers taken substantially along the line 99 of FIG. 2.

FIG. It) is a perspective view of a portion of the moldboard spreadermechanism.

FIG. I l is a vertical sectional view taken substantially along the lineIll-11 ofFIG. 2. I

FIG. 12 is a fragmentary elevational view of the hinging of the spreaderarms to the moldboard as viewed substantially along the line I2]l2 ofFIG. 2.

FIG. I3 is a schematic sectional view taken substantially along line13-13 of FIG. 4 and showing the wheels in different positions ofelevation.

FIG. I4 is a fragmentary elevational view substantially along the lineI4I4l of FIG. 4 showing a portion of the mounting of the spoiler bladeand ground wheels.

FIG. I5 is a fragmentary perspective view of the structure of FIGS. l3and M, showing the rear wheels and spoil blades in working position.

FIG. 16 is a view similar to FIG. I5, showing the members in transportposition.

FIG. 17 is a schematic cross-sectional view of a typical ditch dug bythe machine.

The machine which is the subject of the present invention consists of aplurality of sections hinged together about axes and in sequenceshereinafter described in detail. The front portion of the excavatingsections comprises a fixed lister 21 which is a pointed plowlike memberwhich is normally horizontal disposed and which first enters the ditch.In advance of the lister 21 is a steering section 22 which is pivotallyattached to the front of the lister and controls the depth and directionof movement of the lister, being dragged by one or more tractors. Behindthe fixed lister 21 and to either side thereof are adjustable listers 23hinged thereto about vertical pivot axes. The angles of the adjustablelisters relative to the fixed listers determine the width of cut of thebottom of the ditch. Behind each of the adjustable listers is amoldboard 24, an elongated blade which slants upwardly and outwardly andexcavates the side of the ditch, controlling the slope and widththereof. The position of the moldboard relativeto the adjustable listeris controlled by moldboard spreader assembly 26, the front end of whichis pivotally connected to the fixed lister and the back of which isconnected to the moldboard. At the rear of each moldboard is an assembly27 which comprises ground engaging wheels which rest upon the bankoutside of the confines of the ditch and also in advance of each wheel aspoiler blade which smooths the bank to form a path for the wheels.

The various sections heretofore mentioned will now be described inorder.

FIXED LISTER Fixed lister 21 supports on its top a motor 31 and ahydraulic pump 32. The bottom edge 33 of the lister is horizontal,preferably having a hardened blade 34 on either side. Blades 34 convergeforwardly as viewed in plan. The back 36 is vertical and transverse.Viewed in side elevation (FIG. 1) the prow 37 slopes from bottom edge 33upwardly rearwardly to a radius 38 and then the portion 39 above radius38 slopes upwardly forwardly. The width of prow of lister 21 determinesthe minimum width of the bottom of the ditch being dug.

Lister 21 above edge 39 has a pair of forward extending apertured pads41 to which is attached drawbar 42 pivoted about a horizontal transversepin 43. Above lister 21 is a bracket 44 to which is pivotally mountedhydraulic cylinder 46, the rod 47 of which is pivotally connected to apad 48 on drawbar 42. Extension and retraction of rod 47 controls theangle of drawbar 42 relative to lister 21.

STEERING TONGUE In advance of drawbar 42 is steering tongue assembly 22.Said assembly has a chassis'Sl which is connected to the forward end ofdrawbar 42 by a vertical kingpin 52. Chassis 51 is supported byhorizontal axle 53 to the outer sides of which are wheels 54 whichengage the ground ahead of the machine. The forward end of chassis 51 isformed with clevis arms 56 and between arms 56 is a link 57 pivotallyconnected thereto by shaft 58. Steering tongue 61 is connected to link57 by means of vertical pivot shaft 62. At the forward end of tongue 61is a towing eye 63 connected thereto by a transverse pin 64. Eye 63 maybe connected to a tractor or other towing implement. Where a pair oftractors are used, hooks 66 are connected to the forward end of tongue61 and the cables may be used to connect each hook 66 to a tractor orother towing instrumentality.

Steering of tongue 61 relative to drawbar 42 is accomplished by means ofsteering cylinders 67 on either side of tongue 61. The rearward end ofeach cylinder 67 is connected to eye 68 on shaft 58. The rod 69 of eachcylinder 67 is connected to a bracket 71 on tongue 61. The cylinders 67on opposite sides of the machine are double acting and are crossconnected so that the left-hand rod 69 is advanced and the right-handrod 69 retracted in equal distances and vice versa.

The function of the steering assembly is as follows: As the tractor ortractors pull tongue 61, actuation of cylinders 67 controls the angle oflink 56 relative to the tongue and this in turn controls the directionof wheels 54. Since drawbar 42 is directly connected to chassis 51, theentire machine follows in line depending upon the energization of thecylinder 67. As will hereinafter be explained, rear wheels are socontrolled that they follow the direction of front wheels 54. Inaddition to controlling the direction of movement of the machine,cylinder 46 also determines the depth of cut of front lister 21. Thusthe operator by energization of the cylinders 67 and 46 determines boththe direction and depth of lister 21.

ADJUSTABLE LISTERS Immediately behind the rear end 36 of lister 21 arethe adjustable listers 23 which are movable between a longitudinallyextending position wherein the ditch is of minimum bottom width to anoutward projecting position where the width of the bottom is maximum.The bottom edge of each adjustable lister 23 is coplanar with the bottomedge 33 of lister 21. A vertical pivot shaft 77 interconnects the frame78 of each adjustable lister with front listers 21. A plate 79 ispivotally connected by means of pivot 81 to the back 36 of lister 21.Pivoted to the back 36 is hydraulic cylinder 82, the rod 83 of which ispivoted to the outer end of plate 79. Plate 79 on its undersurfacecarries sockets 84 which receive balls 86 on the inner ends of arms 87.The outer ends of arms 87 have ball and socket joints 88 which areconnected to the bottom edge of adjustable lister 23. When cylinder 82is energized, rod 83 is extended and plate 79 is depressed, forcing thearms 87 outward and spreading the adjustable listers to pivot abouttheir vertical pivots 77. In this manner, the width of the bottom of theditch may be controlled.

MOLDBOARD Moldboard 24 comprises an elongated hollow member on eitherside of the machine which is connected immediately behind adjustablelister 23. The frame 76 of adjustable lister 23 at its rearward endhas.an arm 91 carrying a vertical pivot shaft 92 which is connected tohorizontal arm 93 extending from vertical brace 94. The lower end ofbrace 94 carries a horizontal pivot 96, the outer end of which hasvertically upward portion 97 received in eye 98 attached to bracket 99which is an extension of frame 76. Pivot 96' and portion 97 aresometimes referred to herein as an L-shaped pivot. Pivoted about shaft96 is a pivot plate 101 having an arcuate upper surface 102 and receivedbetween member 94 and a guide 103 depending from underside of arm 93.

Plate 101 is fixed to the back of the hollow moldboard frame 106. Byactuating means hereinafter described in detail, moldboard 24 is pivotedabout shaft 96 and also about axes 92, 97, it being understood that theaxes of shafts 92 and 97 are in vertical alignment and that theyintersect the axis of pivot 96. It is a function of the hinging of themoldboard 24 relative to adjustable lister 23 to permit the moldboard toassume any angle relative to the horizontal depending upon the depth ofthe ditch being dug and further to permit the moldboard to swinginwardly and outwardly about the vertical axes 92, 97 to control thewidth of the ditch. The actuation means is next described.

MOLDBOARD ACTUATING MECHANISM Means is provided for elevating therearward end of the moldboard 24 and also for adjusting its spread.Extending rearward from lister 21 is guide 111 which is preferably apiece of rectangular mechanical tubing in which various hydraulic hosesand controls are housed. The forward end of guide 11 1 is pivoted to therear surface 36-of lister 21 about a horizontal transverse pivot 1 12.Immediately below and parallel to tube 1 11 is a bar 113 pivoted to end36 about pivot 114. Vertical alignment guides 116 depend from guide 111and maintain bar 1 13 in alignment.

At the rear of guide 111 is a subframe designated generally by referencenumeral 117 comprising two spaced-apart vertical members 118 connectedtogether at their tops by transverse member 119. The back end of guide111 is pivoted to members 118 by transverse horizontal pivot 121 and thebar 113 is pivoted by pivot 122. The spacing between pivots 121 and 122is identical to that between pivots 112 and 114 and hence members 111and 113 are at all times parallel. Such arrangement insures that members118 are at all times vertical, and thus parallel to back 36 despiteangular variation of guide 1 11. I

At the forward end of guide 111 are depending arms 126 which receive theend of rod 127 of cylinder 128, the forward end of which is pivotallyconnected to pad 129 on back 36. Energization of cylinder 128 controlsthe vertical inclination of guide 111 and this in turn, as hereinafterexplained, controls the inclination of the moldboards 24. It will beunderstood that cylinder 128 is merely one of several means whereby thepitch of guide 1 11 may be controlled.

Subframe 117 contains a horizontally disposed fabricated member 131formed with a downwardly opening slideway 132 in which reciprocatesslidable crosshead 133. Crosshead 133 has outward projecting lugs 134 oneither side at its front. The rearward end of crosshead 133 is connectedto the rod 136 of horizontal cylinder 137 which is supported on subframe117. Energization of cylinder 137 causes movement of crosshead 133 inslideway 132.

Pivoted to subframe 117 is a first spreader link frame 141, said framereceiving vertical pivot axes 142 at the top and 143 at theb0tt0m,-respectively. It is important that link frame 141 as well aslink frame 146 which is pivoted thereto are at all times vertical. Frame146 is pivotally connected to frame 141 by vertical pivot shaft 147. Apin sleeve 148 surrounds pin 147 at the junction of link frames 141 and146. A connecting rod 149 is pivotally connected to lug 134 and also tosleeve 148.

Moldboard 24 approximately two-thirds rearward of its forward end isprovided with a plate 151. Pivoted to plate 151 by horizontal pivot 152is a bracket 153 having an overhanging lip 154 which is on the inside ofplate 151. The outer ends of link frame 146 are pivotally connected tocars 156 on bracket 153 by means of vertical pivot 157. Movement ofcrosshead 131 therefore causes inward and outward movement of moldboard24, the link frames 141, 146 pivoting around the axes 142-143, 147 and157 in a grasshopper linkage movement which is illustrated schematicallyin FIG. 4. In the solid line position of FIG. 4 the link frames 141 and146 are extended outwardly almost their entire extent of travel, whereasin dotted line position they are folded to a position where themoldboards 24 are parallel to guide 111 and of minimum width.

Auxiliary to the cylinder 137 on either side of the machine is acylinder 161 connected to a bracket extending rearward from members 118with its rod 162 connected to hinge sleeve 148. Cylinders 161 havecommon connections with cylinder 137 and assist the latter in foldinglink frame 146 and thus in moving the moldboards inward and outward.

Subframe 117 also is provided with a cab 166 elevated above guide 111and containing an operators seat 167 and a console 168 having aplurality of valve levers for energization of the various hydrauliccontrols which are installed on the machine. It is a feature of theconstruction that the cab 166 is always horizontal by reason of the factthat subframe 117 is likewise always horizontal. Further, the seat 167is elevated above the level of motor 31 and pump 32 so as to give theoperator an unobstructed view forwardly of the machine. However, themoldboards 24 are elevated at a steeper slope than the guide rod 111,and hence the seat 167 is generally below the level of the moldboardsduring normal operation of K the machine.

REAR WHEELS AND SPOILER BLADES On the rear end of each moldboard 24 arehinge brackets I 201 receiving hinge pin 202. Also received by pin 202is an upper arm 203 which extends inward and is connected to downwardbracket 204. The lower end of bracket 204 is connected to rod 206 ofcylinder 207, the forward end of which is pivotally connected to themoldboard. The lower end of bracket 204 receives shaft 208, the innerend of which is connected on pin 202. The forward end of wheel mountingplate 213 pivots on shaft 208. The rearward end of plate 213 carriesaxle 214 on which is mounted rear wheel 216. Cylinder 221 is pivoted atits forward end to a sleeve 222 on pin 202 which is fixed by brace 220to bracket 204 and the rod 223 of cylinder 221 is connected to therearward end of plate 213. Hence energization of cylinder 221 pivotsplate 213 relative to shaft 208 and thus raises and depresses the wheel216 relative to the moldboard 24.

Also on hinge pin 202 are hinge ears 231 connected to L- shaped bracket232. Spoiler blade 236 is pivoted to bracket 231 about pivot 237.Cylinder 238 is connected at one end to bracket 232 and its rod 239 isconnected to spoiler blade 236. Energization of cylinder 230 thus causesblade 236 to swing about pivot 237. About midway outward of spoilerblade 236 is a guide 241 which is vertically disposed in the horizontalposition of blade 236. The outer edge of L-shaped bracket 232 isreceived in guide 241. Hence as blade 236 pivots around pivot 237, it iskept in contact with bracket 232. Tie rod 242 is connected at its outerend by means of swivel joint 243 to the outer end of bracket 232 and atits inner end by means of swivel joint 244 to wheel mounting plate 213.Tie rod 242 performs two functions. In normal usage of the machine itprovides a brace supporting the blade 236 against the thrust imposedupon it. Its second function is in transportation. When the machine isbeing transported from one location to another, wheel 216 is depressedand rod 239 contracted. Tie rod 242 pulls blade 236 and wheel 216 inrelationship to each other so that the blade is automatically pivotedabove the level of wheel 216 and inward, as is best shown in solid linesin FIG. 14. Hence the blade 236 does not project outward beyond wheel216 and highway width of load requirements are observed.

As has previously been noted, it is desirable that wheel 216 be pointedin the same direction as wheels54 despite changes in position ofmoldboards 24. The body 246 of the hydraulic valve controlling cylinder207 is mounted for sliding in a longitudinal direction on slide 247fixed to blade 24. The conventional hydraulic valve spool 248 of valvebody 246 siides within said body. The forward end of spool 248 isconnected by universal joint 249 to rod 251 and the forward end of rod251 is connected to an ear 252 which pivots with frame 146. The rearwardend of spool 248 is connected by universal joint 253 to rearwardextending rod 254, the rearward end of which is connected by pivot 256to bracket 204. As the spool 248 is moved within body 246, dependingupon the positions of rods 251 and 254, energization of cylinder 207 islikewise controlled. The hydraulic connections between valve body 246and cylinder 207, as will readily be understood by one skilled in thehydraulic control art, are such as to center spool 248 within valve body247. Hence despite movement of mold board 24 relative to the axis 154,bracket 204 is swung about axis 202 to maintain shaft 208 and hence tomaintain axle 214 parallel to axle 53. The mounting of body 246 on slide247 accommodates the vertical component of the movement of themoldboard.

OPERATION In normal operation of the device, the operator seated on seat167 manipulates the hydraulic controls 168 which govern the variousdouble-acting hydraulic cylinders which are energized from pump 32driven by motor 31. One or more tractors pull the machine and cause itto move along the ditch. As the tractors advance, the operator actuatesthe controls for cylinders 67 to steer wheels 54 along the desiredcourse. As has been previously described, automatic means causes therear wheels 216 to be parallel to wheels 54. The operator also controlscylinder 46 to raise or lower lister 21 and all of the elements rearwardof said lister relative to wheels 54 and thus the depth of the ditch iscontrolled. When the lister 21 is at the f desired depth, cylinder 46 isreadjusted to maintain such depth.

Directing attention now to FIG. 17, the width of the bottom of the ditchis controlled by movement inward and outward of adjustable listers 23under the control of cylinder 82. At minimum width, the listers 23 arestraight back from lister 21 and at maximum width they are projected totheir full extension. The width of the top of the ditch and the slope ofthe sides are controlled by the outward movement of moldboards 24 aboutaxes 92, 97. The inclination of the moldboards 24 is controlled bypivotal movement of member 26 about transverse pivot 112 under thecontrol of cylinder 128, or other equivalent control means. As haspreviously been stated, the

swinging movement of member 26 is controlled by parallel bar 113 so thatthe plates 118 are always vertical. The outward swinging movement ofmoldboards 24 about the axes 92, 97 is controlled by cylinder 137 andcylinder 161. The pivot axes are moved toward and away from thecenterline of the machine and this in turn causes the folding of thelink frames 141, 146 in grasshopper fashion which has heretofore beendescribed.

A distinctive feature of the invention is the fact that the rear wheels216 are mounted to ride on the outside of the ditch. Normally the wheels216 are raised to the position of FIG. 15, or the solid line position ofFIG. 13 by actuation of cylinders 221. Spoil blades 236 are adjusted bymeans of cylinder 238 to smooth the bank ahead of wheels 216.

When the machine is to be transported from place to place, it isdesirable that its width be reduced so that it can travel down a highwayor fit in the bed of a truck. Accordingly, the movable listers 23 arepivoted inward so that they are longitudinally aligned and themoldboards 24 are also pivoted inward in longitudinal alignment. The rod223 of cylinder 221 is extended, causing wheel 213 to drop to theposition of FIG. 16. At the same time, the cylinder 238 controllingspoil blades 236 is energized to retract rod 239. Tie rod 242 causes thelower edge of spoil blade 236m move upward and inward, clearing the topof wheel 216 and coming into position parallel to adjustable lister 23and moldboard 24. To further facilitate compact arrangement of themachine during transportation on a truck, the outer end of rods 69 maybe disconnected from brackets 71 and the tongue 61 swung inward towardthe lister, thereby reducing the overall length.

What is claimed is:

1. A ditch building machine comprising a lister section for forming thebottom of a ditch, a moldboard on each side of said machine, moldboardmounting means pivotally mounting said moldboard to the side and rear ofsaid lister section for movement in and out transversely of said machineand also for movement of the rear of said moldboard up and down,moldboard actuating means for pivotally moving said moldboard relativeto said lister section, a pair of rear wheels, rear wheel mounting meansfor mounting one said rear wheel on the rear of each said moldboard,whereby said rear wheels rest on the banks of a ditch while said listersection is on the bottom of said ditch and said moldboards extend alongthe sides of said ditch, said rear wheel mounting means comprising agenerally vertical hinge pin on the rear of said moldboard, a shaftconnected for oscillatory movement with said hinge pin and disposedperpendicular to said hinge pin, a link on said shaft, an axle on theend of said link opposite said shaft, a wheel on said axle, hydraulicmeans interconnecting said moldboard and said shaft to pivot said linkand said wheel about said hinge pin, and valve means for said hydraulicmeans, said valve means responsive to movement of said shaft and of saidmoldboard to automatically pivot said link so that said wheel isparallel to the direction of movement of said machine at any position ofsaid moldboard.

2. A machine according to claim 1, in which said moldboard actuatingmeans comprises a longitudinally extending guide, means pivotallymounting said guide about a transverse horizontal axis to said listersection, guide actuating means for pivoting the rear end of said guideup and down relative to said lister section, a subframe on the rear ofsaid guide, connecting means connecting said subframe to said moldboardsfor raising and lowering the rear of said moldboards relative to saidlister section, said connecting means including two perpendicularlyrelated pivots whereby said subframe remains vertical at all times andsaid moldboard pivots about both horizontal and vertical axes at theforward end of said moldboard.

3. A machine according to claim 2, which further comprises meanspivotally interconnecting said lister section and said subframe parallelto said guide to maintain said subframe parallel to said lister sectionas said subframe moves under influence of said guide actuating means.

4. A machine according to claim 1, in which said valve means comprises aspool, means articulately connecting one end of said spool to saidmoldboard actuating means and means articulately connecting the otherend of said spool to said shaft, said last-mentioned means arranged tomove said valve to energize said hydraulic means to turn said shaft tomaintain the plane of rotation of said wheel parallel to thelongitudinal central plane of said machine as the rear end of saidmoldboard moves in and out relative to said plane.

5. A machine according to claim 1, which further comprises a spoil wingnormally positioned ahead of said rear wheel, means mounting said spoilwing on the rear of said moldboard for pivotal movement about asubstantially horizontal axis, and means interconnecting said moldboardand said spoil wing to pivot said spoil wing about said axis.

6. A machine according to claim 5, in which said means mounting saidspoil wing further comprises a bracket,'means mounting said bracket tosaid moldboard for pivotal movement about said hinge pin and means forpivoting said bracket about said hinge pin to swing said spoil wing inand out relative to said moldboard.

7. A machine according to claim 6, which further comprises a brace,means attaching said brace to said spoil wing for swivel movementrelative to said spoil wing, means attaching said brace to said link forswivel movement relative to said link, whereby upon depressing saidwheel and pivoting said spoil wing up relative to said horizontal axis,said spoil wing is raised above and inward relative to said rear wheel.

8. A machine according to claim 1, in which said moldboard actuatingmeans comprises a longitudinally extending guide, a subframe on the rearof said guide, a hydraulic cylinder having a rod mounted on saidsubframe, and on either side of said machine a first link pivoted tosaid subframe about a vertical axis, a second link pivoted to the outerend of said first link, the outer end of said second link pivoted tosaid moldboard about a vertical axis, connecting means interconnectingsaid rod and said links to move the outer end of said second link in andout relative to said subframe, and means pivotally connecting the outerend of said second link to one of said moldboards.

9. .A machine according to claim 8, in which said first and second linksare connected at a vertical hinge, and said connecting means ispivotally connected to said hinge.

10. A machine according to claim 1, in which said lister sectioncomprises a fixed lister, a movable lister on each side of said fixedlister, means pivotally mounting each movable lister to the side andrear of said fixed lister, and movable lister actuating means for movingsaid movable listers in and out to vary the width of the bottom of saidditch.

11. In a ditch building machine a lister section, a moldboard on eachside of said machine, an Lshaped pivot pivotally connected to the sideand rear of said lister section for pivotal movement of said moldboardabout both a vertical and a horizontal axis, a rear wheel at the rear ofsaid moldboard, a horizontal shaft connected to said moldboard, a linkpivoted to said shaft, an axle on said link, said rear wheel on saidaxle, means for pivoting said link about said shaft to raise and lowersaid rear wheel relative to said moldboard, a bracket pivoted 'to saidmoldboard about a substantially vertical axis, said shaft held by andpivoting with said bracket, means for pivoting said bracket about saidvertical axis, a spoilwing normally positioned ahead of said rear wheel,a second bracket pivotally mounted about said vertical axis to saidmoldboard, means mounting said spoil wing to said second bracket forpivotal taching the other end of said brace to said link, whereby, upondepressing said wheel and pivoting said spoil wing up relative to saidhorizontal axis, said spoil wing is raised above and inward relative tosaid rear wheel.

1. A ditch building machine comprising a lister section for forming thebottom of a ditch, a moldboard on each side of said machine, moldboardmounting means pivotally mounting said moldboard to the side and rear ofsaid lister section for movement in and out transversely of said machineand also for movement of the rear of said moldboard up and down,moldboard actuating means for pivotally moving said moldboard relativeto said lister section, a pair of rear wheels, rear wheel mounting meansfor mounting one said rear wheel on the rear of each said moldboard,whereby said rear wheels rest on the banks of a ditch while said listersection is on the bottom of said ditch and said moldboards extend alongthe sides of said ditch, said rear wheel mounting means comprising agenerally vertical hinge pin on the rear of said moldboard, a shaftconnected for oscillatory movement with said hinge pin and disposedperpendicular to said hinge pin, a link on said shaft, an axle on theend of said link opposite said shaft, a wheel on said axle, hydraulicmeans interconnecting said moldboard and said shaft to pivot said linkand said wheel about said hinge pin, and valve means for said hydraulicmeans, said valve means responsive to movement of said shaft and of saidmoldboard to automatically pivot said link so that said wheel isparallel to the direction of movement of said machine at any position ofsaid moldboard.
 2. A machine according to claim 1, in which saidmoldboard actuating means comprises a longitudinally extending guide,means pivotally mounting said guide about a transverse horizontal axisto said lister section, guide actuating means for pivoting the rear endof said guide up and down relative to said lister section, a subframe onthe rear of said guide, connecting means connecting said subframe tosaid moldboards for raising and lowering the rear of said moldboardsrelative to said lister section, said connecting means including twoperpendicularly related pivots whereby said subframe remains vertical atall times and said moldboard pivots about both horizontal and verticalaxes at the forward end of said moldboard.
 3. A machine according toclaim 2, which further comprises means pivotally interconnecting saidlister section and said subframe parallel to said guide to maintain saidsubframe parallel to said lister section as said subframe moves underinfluence of said guide actuating means.
 4. A machine according to claim1, in which said valve means comprises a spool, means articulatelyconnecting one end of said spool to said moldboard actuating means andmeans articulately connecting the other end of said spool to said shaft,said last-mentioned means arranged to move said valve to energize saidhydraulic means to turn said shaft to maintain the plane of rotation ofsaid wheel parallel to the longitudinal central plane of said machine asthe rear end of said moldboard moves in and out relative to said plane.5. A machine according to claim 1, which further comprises a spoil wingnormally positioned ahead of said rear wheel, means mounting said spoilwing on the rear of said moldboard for pivotal movement about Asubstantially horizontal axis, and means interconnecting said moldboardand said spoil wing to pivot said spoil wing about said axis.
 6. Amachine according to claim 5, in which said means mounting said spoilwing further comprises a bracket, means mounting said bracket to saidmoldboard for pivotal movement about said hinge pin and means forpivoting said bracket about said hinge pin to swing said spoil wing inand out relative to said moldboard.
 7. A machine according to claim 6,which further comprises a brace, means attaching said brace to saidspoil wing for swivel movement relative to said spoil wing, meansattaching said brace to said link for swivel movement relative to saidlink, whereby upon depressing said wheel and pivoting said spoil wing uprelative to said horizontal axis, said spoil wing is raised above andinward relative to said rear wheel.
 8. A machine according to claim 1,in which said moldboard actuating means comprises a longitudinallyextending guide, a subframe on the rear of said guide, a hydrauliccylinder having a rod mounted on said subframe, and on either side ofsaid machine a first link pivoted to said subframe about a verticalaxis, a second link pivoted to the outer end of said first link, theouter end of said second link pivoted to said moldboard about a verticalaxis, connecting means interconnecting said rod and said links to movethe outer end of said second link in and out relative to said subframe,and means pivotally connecting the outer end of said second link to oneof said moldboards.
 9. A machine according to claim 8, in which saidfirst and second links are connected at a vertical hinge, and saidconnecting means is pivotally connected to said hinge.
 10. A machineaccording to claim 1, in which said lister section comprises a fixedlister, a movable lister on each side of said fixed lister, meanspivotally mounting each movable lister to the side and rear of saidfixed lister, and movable lister actuating means for moving said movablelisters in and out to vary the width of the bottom of said ditch.
 11. Ina ditch building machine a lister section, a moldboard on each side ofsaid machine, an L-shaped pivot pivotally connected to the side and rearof said lister section for pivotal movement of said moldboard about botha vertical and a horizontal axis, a rear wheel at the rear of saidmoldboard, a horizontal shaft connected to said moldboard, a linkpivoted to said shaft, an axle on said link, said rear wheel on saidaxle, means for pivoting said link about said shaft to raise and lowersaid rear wheel relative to said moldboard, a bracket pivoted to saidmoldboard about a substantially vertical axis, said shaft held by andpivoting with said bracket, means for pivoting said bracket about saidvertical axis, a spoil wing normally positioned ahead of said rearwheel, a second bracket pivotally mounted about said vertical axis tosaid moldboard, means mounting said spoil wing to said second bracketfor pivotal movement about a substantially horizontal axis, means forpivoting said spoil wing about said horizontal axis relative to saidmoldboard, a brace, a first swivel attaching one end of said brace tosaid second bracket, and a second swivel attaching the other end of saidbrace to said link, whereby, upon depressing said wheel and pivotingsaid spoil wing up relative to said horizontal axis, said spoil wing israised above and inward relative to said rear wheel.